This application claims the priority of German patent document 197 16 865.5, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a nodal connection element formed by internal high pressure forming. The invention also relates to a frame construction which comprises at least one of the nodal connection elements and a plurality of tube-shaped frame elements. The invention also relates to the method of making such a nodal connection element and frame construction.
German Patent Document DE 195 06 160 A1 shows a frame construction for the supporting structure of a vehicle body which is composed of frame elements and nodal connection elements. In this arrangement, the frame elements as well as the nodal connection elements are produced by hydraulic internal high pressure forming of aluminum tube profiles. The frame elements are inserted into or fitted onto the adjacent nodal connection element, where the plug-type connection is additionally secured by welding, gluing, screwing or riveting. This type of frame construction is suitable only for uniform materials, but not for a mixed construction where the frame elements are made of different materials.
Thus, there is a need for a nodal connection element which is connectable with frame elements made of different materials.
This and other needs have been met according to the present invention by providing a frame construction comprising: at least one nodal connection element manufactured by hydraulic internal high pressure forming, the nodal connection element comprising at least two tube-shaped hollow bodies made of different materials, the hollow bodies being nested to define an interior hollow body and an exterior hollow body, the nodal connection element defining at least two connections at which an end of one of the tube-shaped hollow bodies is offset from an end of another of the tube-shaped hollow bodies; and at least two tube-shaped frame elements manufactured by hydraulic internal high pressure forming, each of said frame elements being made of one of said materials, each of said frame elements being pluggably connected with said nodal connection element at a respective of said connections, each of said frame elements being additionally joined to a respective one of said hollow bodies made of the same of said materials at said connections.
This and other needs have also been met according to the present invention by providing a nodal connection element comprising: an exterior tubular hollow body formed by internal high pressure forming a first material; an interior tubular hollow body formed by internal high pressure forming a second material, said second material being different from said first material, said interior tubular hollow body being nested inside said exterior tubular hollow body, said nested hollow bodies defining at least two connection openings, an end of the exterior hollow body being offset from an end of the interior hollow body at said connection openings.
This and other needs have also been met according to the present invention by providing a method of forming a nodal connection element, said method comprising the steps of: (a) internal high pressure forming an exterior tubular hollow body of a first material; (b) internal high pressure forming an interior tubular hollow body nested inside said exterior hollow body, said interior hollow body being formed of a second material which is different from said first material; and (c) cutting ends of said exterior hollow body at an offset from ends of said interior hollow body to define at least two connection openings.
The principal advantages achieved by the invention are that, due to the structure of the internal-high-pressure-formed nodal connection elements, a frame construction is permitted as a mixed construction; that is, frame elements of different materials can be connected to the respective nodal connection element. This permits material combinations, such as steel/aluminum, aluminum/steel, aluminum/magnesium, magnesium/aluminum, and the like. A frame construction of this type is particularly suitable for chassis parts and for the supporting structure of a vehicle body.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.